EXPERIMENTAL RESEARCH ON THE CONSTITUTIVE RELATIONSHIP OF CONCRETE IN A CRYOGENIC ENVIRONMENT

To develop a concrete constitutive relationship under cryogenic conditions, stress-strain curves were developed by sorting test data from the following temperature conditions: 20℃, 0℃, -40℃, -80℃, -120℃, -160℃. Compressive strength, elastic modulus, and peak strain were taken as key indicators in this test. The test shows that specimens are damaged more quickly at lower temperatures, and the descending branch of the curve is shorter than in normal conditions. Moreover, the lower the temperature, the shorter and the steeper the descending branch becomes. From the results, we can conclude that the concrete peak strain drops with decreased temperature, meaning the brittleness tends to increase. Both the compressive strength and elastic modulus increase, but the respective improvement of their performance has to do with the temperature. A third-order polynomial and a rational expression are proposed to describe the rising branch and descending branch, respectively.